enum Genre {
    Rock,
    CountryAndWestern,
    Classical,
    Pop,
    HeavyMetal
}
class MusicCollection {
    private readonly collection: Map<Genre, string[]>;
    constructor() {
        this.collection = new Map<Genre, string[]>();
    }

    public Add(genre: Genre, artist: string[]): void {
        this.collection.set(genre, artist);
    }

    public Get(genre: Genre): string[] | undefined {
        return this.collection.get(genre);
    }
}

let collection = new MusicCollection();
collection.Add(Genre.Classical, [`Debussy`, `Bach`, `Elgar`, `Beethoven`])
collection.Add(Genre.CountryAndWestern, [`Debussy`, `Bach`, `Elgar`, `Beethoven`])
collection.Add(Genre.HeavyMetal, [`Tygers of Pan Tang`, `Saxon`, `Doro`, `Beethoven`])
collection.Add(Genre.Pop, [`Debussy`, `Bach`, `Elgar`, `Beethoven`])
collection.Add(Genre.Rock, [`Debussy`, `Bach`, `Elgar`, `Beethoven`])
console.log(collection)
console.log(collection.Get(Genre.HeavyMetal))